clinical features
Last reviewed 01/2018
The clinical signs of partial paralysis of one lateral rectus muscle can be shown by getting the patient to follow your finger:
- on lateral gaze, the patient will be aware of double vision
- squint may be obvious to the observer
To distinguish the eye with the paresis, get the patient to cover one eye and then the other. The eye with the lesion is the one which causes, when covered, the most lateral image to disappear.
Check the limit of abduction with one eye covered compared with when both eyes are observed - if the eye abducts a little further with monocular testing, it suggests that the lesion is an inter-nuclear ophthalmoplegia - i.e. in the brainstem, rather than a pure VI nerve paresis.